SPL No Longer Required

• By John K. Waters
• November 30, 2006

The denizens of Silicon Valley were wandering around in the traditional post-Turkey-Day, tryptophan-induced haze this week (seasoned with just a dash of the-long-weekend-could-have-been-longer grumpiness). But the Brits don't celebrate Thanksgiving, so I found Sun Microsystems' chief open-source evangelist, Simon Phipps, sharp as ever (despite his cold) when I snagged some time with him on the phone today. I wanted to hear about the latest Sun-authored open-source license sent into retirement.

''It's been my cunning plan for some time to retire old open source licenses at Sun,'' the indefatigable Phipps told me. ''This is the last of them.''

Sun has officially retired the Sun Public License (SPL). The Santa Clara, CA-based systems company contacted the Open Source Initiative (OSI), the non-profit corporation that manages and promotes the Open Source Definition, and requested that they consider it ''retired.'' Sun migrated the last large codebase--its NetBeans IDE--from the SPL last spring. The company now considers it a historical artifact.

Ta-daaa! ...yeah, I know. It's sort of an anticlimactic announcement after the company open sourced the Java Platform, but this is yet another piece of the evolving open-source story.

OSS licensing is notorious for confusing terms and quirky conditions. I think there are about 50 OSI approved open-source licenses floating around right now. There's a big list on the OSI website.

Why so many? Phipps points to restrictions in the popular Mozilla Public License (MPL), which was developed for the original Mozilla browser in the late 1990s. This is a reciprocal license, which requires modifications to be given to the community, and it explicitly names Mozilla as the owner of the code. Organizations not too keen on that idea have modified the otherwise nifty license, usually changing just two things: the name of the owner of the code, and the choice of law and venue, which is hard-coded as Santa Clara, CA, where Mozilla is based. The result was a swarm of ever-so-slightly-different ''vanity'' licenses.

Sun has been exploring licensing models for ages. In the 1990s, they licensed JINI in a way that would give the community freedom to edit it while giving it coherence. The company created the Sun Industry Standards Source License, or SISSL, under which the OpenOffice Suite was originally licensed. Last year the OSI approved Sun's own variation of the MPL, the Common Development and Distribution License (CDDL), which the company created for its OpenSolaris operating system and its Glassfish project.

SISSL got the gold watch last year. If you go to the SISSL page of the OSI website you'll find a bright red ''Sun has ceased to use or recommend this license,'' just above the definitions.

The CDDL, however, seems to have real job security. Sun still views it as the last Mozilla-type license. ''The only reason there's any question at all about the CDDL is that we wrote it,'' Phipps says, ''and some people want to make an issue out of that. Anyone who's actually read the license would see that there's no problem with it. The CDDL parameterizes the details in the Mozilla license that were causing people to create vanity licenses. Its purpose is to make sure that nobody ever has to write a vanity license again.''

Sun considered licensing Java under the CDDL, but opted for the GNU General Public License, because of its potential for growing the market for the Java Platform. Growing that market was the company's primary objective, Phipps says, and that objective was best met with the GPL.

''We're not doctrinaire about licensing,'' Phipps adds. ''My mantra is, the right license for the right community.''

Phipps is now encouraging other creators of Mozilla-derived licenses to send them to the rest home. In his blog, he writes: ''I'd encourage the (many) other creators of Mozilla-derived licenses to take the same step. We owe it to our colleagues in the open source community to keep things simple.''

Apparently, if you're the copyright holder of a license, all you have to do is call up the OSI and declare that the license is retired.

BTW: The SPL and even SISSL are still OSI approved licenses; they don't actually get unapproved.